1. Field of the Invention
The present invention relates to a planographic printing plate packaging structure for accommodating and packaging planographic printing plates which have one surface formed as an imaging surface in a packaging box which includes a portion for taking out printing plates and the like accommodated therein, and to a method for packaging planographic printing plates.
2. Description of the Related Art
In plate making methods of recent years (including electrophotographic plate making methods), planographic printing plates such as photosensitive printing plates or heat sensitive printing plates are widely used in order to facilitate automation of a plate making process. A planographic printing plate is produced by performing surface treatments such as graining, anodic oxidation, silicate treatment, or other chemical conversion treatment solely or in combination as necessary on a substrate which is typically a sheet-shaped or coil-shaped aluminum plate, and then coating a photosensitive layer or a heat sensitive layer (these are referred to as “coating film”) thereon, drying, and then cutting to a desired size. This planographic printing plate is subjected to a plate making process including exposure, development, gum coating and the like, then set in a printing machine, coated with ink, thus, texts, images and the like are printed on pieces of paper.
When this planographic printing paper is handled, in order to reduce a frequency of handling so as to perform transportation and storage of the planographic printing paper at low costs, a large number of planographic printing plates may be stacked in a thickness direction to form a stack of planographic printing plates and the stack is then accommodated and packaged in a packaging box.
In FIG. 9, an example of the planographic printing plate packaging structure in which a stack of planographic printing plates is accommodated and packaged in a packaging box 410, is illustrated (see Japanese Patent Application Laid-Open (JP-A) No. 2000-95271).
In this packaging box 410, after a base pad 414 is attached to a base plate 412, side plates 416 and apical plates 418 provided from and in connection with a periphery of the base plate 412 are folded so as to wind around core materials 420. A frame 422, as well as a receiving space 424 formed inside the frame 422, is thus formed. Moreover, a base rug pad 426 is further attached to a base pad 414, and a photosensitive material 428 is received in the receiving space 424. Thereafter, a roof pad 430 which has been attached to a roof plate 432 is fitted into an inner side of the frame 422 and the roof plate 432 is fixed to the box body with an adhesive tape or the like.
Depending on an apparatus in which a planographic printing plate is used, a planographic printing plate whose one side surface is formed as an imaging surface may be set in an apparatus in a state in which the imaging surface thereof is directed downwardly.
However, in the above-described conventional planographic printing plate packaging structure in which the packaging box 410 and the like are used, planographic printing plates are accommodated in the packaging box 410 in a manner such that the imaging surfaces of the planographic printing plates face the roof plate 432 (the imaging surfaces of the planographic printing plates are directed upwardly in FIG. 9). Therefore, it is necessary for a user to turn the planographic printing plates over after opening the packaging box 410 to set the planographic printing plates in an apparatus, and this has become a large operational burden.
Further, the planographic printing plate generally has a thin plate form (for example, a thickness of approximately 0.1–0.5 mm). Because of that, there has been a case in which the planographic printing plate receives external force locally during a reverse operation and is thereby deformed.
Furthermore, even in a case in which the planographic printing plate was not deformed, there has been a case in which a coating film was peeled off from a substrate by external force.
In order to prevent the planographic printing plate from such deformation and to prevent the coating film of the planographic printing plate from peeling off, it has been necessary for a user to perform operations such as reversing the planographic printing plate and loading the planographic printing plate on an apparatus with extreme care, and this has further increased the operational burden on the user.